In Patent Literature 1, there is disclosed a switch device including a plurality of line cards (cards A and C in Patent Literature 1), each equipped with an FDB, and also including a second card. The second card includes a management unit that collects the FDB information (FDB learning information) from the line cards to return the so collected information to the line cards.
In the system of the switch device of Patent Literature 1, there are cases wherein a frame containing the FDB information (FDB learning information) is dropped due to the band limiting function innate to the device. Thus, in Patent Literature 2, a transmission rate limiter circuit is equipped on each line card to enable the FDBs to be synchronized positively with one another.